The present invention relates generally to industrial or motive power batteries, and more particularly, to the portion of the assembly process of those batteries wherein completed positive and negative plates and separators are stacked and formed into fused battery stacks having terminal posts projecting therefrom which are subsequently assembled into completed batteries by first placing the completed battery stacks into battery jars, by sealing the battery jars having the battery terminal posts extending therefrom, and finally, by interconnecting the protruding terminal posts of various battery stacks to those of adjacent battery stacks to form a completed battery.
The present invention does not relate to the formation of welds or electrical connections between the battery terminal posts of adjacent battery jars, such as described in U.S. Pat. No. 3,908,742, which describes the prior art hand burning process which has generally been in use to form such connections. Rather, the present application is directed to the field of stacking, aligning, burning and transferring battery stacks into each individual battery jar prior to the completion of the remaining steps in the battery assembly process.
Previously, battery stacks have been formed by hand usually by interleaving positive and negative plates and separators into a three-surfaced container which was tilted slightly out of the horizontal in order to facilitate the alignment of the plates and separators with respect to each other. Once an appropriate number of battery plates and separators were present within the stacking container, the unfused battery stack was then removed from the container by hand and transferred to any of a number of different apparatuses intended to facilitate the burning of battery straps thereon. The battery straps were formed as follows: protruding from the top terminal edge of each of the negative and positive plates on different respective sides of the battery stacks are formed terminal lugs which protrude beyond the top terminal edge of the battery stack; around these terminal lugs are clamped appropriately configured rails or combs to form a mold for subsequently melted lead. An operator using a hand torch adjusted to a neutral or slightly carbonizing flame then melts the portions of the lugs extending up through the mold, adding lead from a suitable supplemental source in order to completely fill the mold into a bar or strap which extends completely across the plates to be formed into a single stack, and further to fuse into that strap an adjacent terminal post which, upon later assembly, will extend through the top cover of the battery jar to facilitate connection with an adjacent battery jar to complete the final battery. In accomplishing this hand burning process an operator is careful to preheat the lugs so that upon melting cold runs will be avoided, and further, following the filling of the mold area with molten lead to allow that lead to puddle in order to form a uniform homogeneous weld. The combs or molds are then removed from the stacks and the fused stack is transferred, normally by hand, to its intended battery jar, which stack is inserted into the battery jar by placing a funnel-shaped guide over the top opening of that jar and feeding the bottom of the completed stack into that funnel-shaped guide, and pushing the stack down into the jar to its intended operating position.
Alternatively, it has been suggested to automate the combs described above by introducing the stacks into a machine which will elevate the stacks between the combs and then, in scissors-like fashion, move the combs together to surround the appropriate lugs. Therefore, introduction of the plates in such machines is accomplished by hand loading the stacks in a direction substantially perpendicular to the axis of the combs and under the combs, and then elevating the stacks so that the lugs extend between the combs prior to closure thereof. While this technique has met with some success, it has heretofore been difficult to properly align and space the lugs with respect to each other so that they properly engage the combs upon closure of the combs therearound. This is explained in part by the fact that industrial storage battery plates are substantially longer and wider than automotive battery plates, and therefore are likely to bend or warp slightly along their length and width, particularly when subjected to a mechanical pasting operation and subsequent wrapping with microporous materials.
Due to the ever increasing size of industrial battery plates and due to the fact that the above described prior art processes necessitated picking up stacks of many interleaved plates and separators, back injuries to workers in industrial battery plant operations were extremely numerous and have represented during recent years a serious production problem. Furthermore, the constant moving of lead plates and separators from station to station encourages the generation of lead and lead oxide dusts which, if inhaled in excessive quantities, may become a health problem. Finally, due to the nature of the hand operations involved in the construction of industrial storage batteries, the quality of any given production run was likely to be dependent upon the skill of the particular workmen assigned to that run.